Valve Lash Adjuster Noise Diagnosis - Suzuki 2000 Grand Vitara SQ625 Service Manual

6A4-44 ENGINE MECHANICAL (J20 ENGINE)
CAUTION:
D Don't turn camshafts or start engine (i.e., valves should not be operated) for about half an hour after
reinstalling hydraulic valve lash adjusters and camshafts. As it takes time for valves to settle in place,
operating engine within half an hour after their installation may cause interference to occur between
valves themselves or valves and piston.
D If air is trapped in valve lash adjuster, valve may make tapping sound when engine is operated after
valve lash adjuster is installed. In such a case, run engine for about half an hour at about 2,000 –
3,000 r/min., and then air will be purged and tapping sound will cease. Should tapping sound not
cease, it is possible that valve lash adjuster is defective. Replace it if defective.
If defective adjuster can't be located by hearing among 16 of them, check as follows.
1) Stop engine and remove cylinder head cover.
2) Push adjuster downward by hand (with less than 20 kg or 44 lbs force) when cam crest is not on
adjuster to be checked and check if clearance exists between cam and adjuster. If it does, adjuster
is defective and needs replacement.

VALVE LASH ADJUSTER NOISE DIAGNOSIS

In case of the followings, valve lash adjuster noise may be caused
by air trapped into valve lash adjusters.
D Vehicle is left for 24 hours or more.
D Engine oil is changed.
D Hydraulic lash adjuster is replaced or reinstalled.
D Engine is overhauled.
If noise from valve lash adjusters is suspected, perform the follow-
ing checks.
1) Check engine oil for the followings.
D Oil level oil pan
If oil level is low, add oil up to Full level hole on oil level gauge.
D Oil quality
If oil is discolored, or deteriorated, change it.
For particular oil to be used, refer to Section 0B.
D Oil leaks
If leak is found, repair it.
D Oil pressure (refer to Oil Pressure Check in this section)
If defective pressure is found, repair it.
2) Run engine for about half an hour at about 2,000 to 3,000 r/min.,
and then air will be purge and tapping sound will cease.
3) Should tapping sound not cease, it is possible that hydraulic
valve lash adjuster is defective.
Replace it if defective.
If defective adjuster can't be located by hearing among 16 of
them, check as follows.
i) Stop engine and remove cylinder head cover.
ii) Push adjuster downward by hand (with less than 20 kg or
44 lbs. Force) when cam crest is not on adjuster to be check
if clearance exists between cam and adjuster.
If it does, adjuster is defective and needs replacement.